Combination burglar alarm and fire alarm system

ABSTRACT

The system includes fire alarm and burglar alarm portions and a common power supply therefor. The burglar alarm portion includes (1) alarm sensors and an alarm circuit for generating signals in response to the operation thereof; (2) a &#39;&#39;&#39;&#39;panic&#39;&#39;&#39;&#39; portion, operable by an individual anywhere in the premises protected, and connected to the alarm circuit and operable thereby whether power is directly connected thereto or not; and (3) status lights and power switch combinations dispersed throughout the premises to display the status of the system. The fire alarm portion includes sensors dispersed throughout the premises and an alarm signal generating circuit.

United States Patent [1 1 Schubert [451 May7, 1974 1 1 COMBINATION BURGLAR ALARM AND FIRE ALARM SYSTEM [75] Inventor: Howard C. Schubert, Leonia, NJ.

[73] Assignee: Aerolite Electronics Corporation,

Union City, NJ.

[22] Filed: Aug. 21, 1972 [21] Appl. No.: 282,245

REMOTES 325 BURGLAR ALARM To Other Templates 321 SIGNAL GENERATING ClRCUlT Primary ExaminerThomas B. Habecker Attorney, Agent, or Firm-Robert Green [5 7 ABSTRACT The system includes fire alarm and burglar alarm portions and a common power supply therefor. The burl rm P9 119 n udes lalarm smsmsa an alarm circuit for generating-signals in response to the operation thereof; (2) a panic portion, operable by an individual anywhere in the premises protected, and connected to the alarm circuit and operable thereby whether power is directly connected thereto or not; and 3) status lights and power switch'combinations dispersed throughout the premises to display the status of the system. The fire alarm portion includes sensors dispersed throughout the premises and an alarm signal generating circuit.

11 Claims, 1 Drawing Figure l l l Fire Alarm Circultl Thermostats 850] 840 J v PANIC 63o ClRCUlT 490 T T r 88 FIRE ALARM COMBINATION BURGLAR ALARM AND FIRE ALARM SYSTEM BACKGROUND OF THE INVENTION Burglar and fire alarm Systems are well known in the art; however, none is as inexpensive to operate or as versatile in the number of functions which can be performed as is the present invention.

SUMMARY OF THE INVENTION Briefly, the invention comprises a burglar-fire system which includes interrelated burglar and fire alarm operating modules and auxiliary operating adjuncts therefor.

DESCRIPTION OF THE DRAWING The single FIGURE is a schematic representation of 'an electronic system embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The system of the invention includes a primary power source such a battery which provides power for the entire system which includes aburglar alarm portion and a fire alarm portion.' The burglar alarm posite end connected to the other end of the horn. A

second diode is connected, oriented as shown, between opposite ends of the coils. Preferably, the arrangement is anodes of the diodes to the silver wire and cathodes of the diodes to the copper wire. This filter eliminates the high positive spikes which might be generated with a magnetic bell or horn due to induced magnetic fields and systeresis effects.

The burglar alarm portion of the invention includes a signal module shown enclosed in dash lines for generating an alarm signal which can be coupled to a remote receiver, for example, at a police station. This module is shown and described in US Pat. No. 3,603,947 and includes two semiconductor switches and 110, for example, G. E. Type 4987 silicon unilateral switches. These SUS devices are planar, monolithic, integrated circuits having thyristor electrical characteristics closely approximating those of an ideal four-layer diode. SUS switch 100 has its anode A con nected through resistor to a positive bus and its gate G connected through a resistor to a negative bus 150. The switch 110 has its anode A connected to positive bus 130 and its gate G connected (1) through a resistor 153 to the positive bus 130, and (2) through a resistor to bus and thence to a relay 520 to be described. The cathode K of SUS switch 100 is connected to a bus 180, and the cathode K of SUS switch 110 is connected 1) through a resistor to one emitter 200 ofa unijunction transistor (UJT) 210, and (2) through a resistor 220 to the slider 223 and to one end of a potentiometer 230, the other end of the potentiometer being connected (1) to the emitter 240 of the unijunction transistor 210 and (2) through a capacitor 250 to the negative bus 150.

The second base 260 of the unijunction transistor is connected by lead 262 to bus 180, and this junction point 264 is connected through a resistor 27.0 to bus 150. The second base 260 of the unijunction transistor 210 is also connected to the gate of silicon controlled rectifier SCR 280, the cathode of which is connected to negative bus 150, and the anode of which is connected (1) through resistor 290 to positive bus 130, and (2) by lead 300 to the cathode of diode 80 of the filter 40. Lead 300 from the anode of SCR 280 is connected by lead 310 to a suitable remote signal or alarm circuit 320, as shown in the aforementioned patent.

The positive bus 130 is connected'to the anode of diode 80 and to the associated end of winding 70 of filter 40. i

The burglar alarm system includes a plurality of light and switch templates 321 dispersed throughout the premises and each including a lamp 322, a switch 323, and a lamp 324. One end of each of these elements is connected to a bus 325, and the other end of each lamp 322 is connected to bus 326, the other end of each switch 323 is connected to bus 327, and the other end of each lamp 324 is connected to a bus 328. The switches 323' are preferably key-operable by an occu pant of the premises.

The burglar alarm portion also includes a single pole,

double throw relay 330 including a winding 340 with a diode 342 across it, an armature 350, and two contacts 360 and 370 (armature 350 is normally closed on contact 360), and armature 380 and two contacts 390 and 400 (armature 380 is normally closed oncontact 390). Armature 380 is connected l through a resistor 410 to a lead 420 which extends from contact 390 to the gate of SUS 100,,and (2) through lead 430 to a series of normally closed switches S1 and finally through lead 440 to bus 450 which extends from the positive terminal of battery 20. Switches S1 represent burglar sensing elements dispersed throughout the premises being protected, and associated with windows, doors, and the like represented by numeral 455, and they may be mechanical switches, ultrasonic devices, infrared devices, or the like. Contact 400 is connected to lead 326 associated with lamps 322 of templates 321.

- Referring again to relay 330, armature 350 is connected by lead 460 to bus 450 and thus to the positive terminal of battery 20, and contact 360 is connected by lead 470 to positive bus 130 and to bus 326 connected to one side of each lamp 324 of templates 32lwhich are dispersed throughout the premises. The cathode of diode 342 and end 343 of the winding 340 are connected to bus 329 to switches 323 of templates 321. The other end 345 of the winding 340 and the anode of diode 342 are connected to bus 450 and to the positive terminal of battery 20.

The burglar alarm portion also includes a circuit portion associated with an entry and exit door 480 to the premises. This circuit portion includes a switch 490 associated with the door 480 and adapted to close when the door is opened and open when the door is closed. This portion of the system also includes l) a lamp 500 and a normally-open, key-operated switch 510 connected together at one end, 501 and 511, respectively, and (2) a relay 520 including a winding 530 paralleled by diode 533, two contacts 540 and 550,'and an armature 560 which is normally closed on contact 550. One end 532 of winding 530 is connected (I) by leads 563 and 570 to positive power bus 450, and (2) by lead 580 to end 503 of lamp 500. The connected ends 501 and 511 of lamp 500 and switch 510, respectively, are connected by lead 590 to commonly connected end 534 of winding 530, the cathode of diode 533, and contact 540 of relay 520. The other end 513 of switch 510 is connected (I by lead 600 to the armature 610 of door switch 490, and (2) by lead 630 to bus 150. The other contact 620 of door switch 490 is connected by lead 640 to the armature 560 of relay 520. Contact 550 of relay 520 is connected to lead 170 which is connected through resistor 160 to the gate of SUS 110 of signal module 90.

The burglar alarm portion of the system also includes a panic module 640 which comprises two silicon controlled rectifiers (SCRs) 650 and 660 having their anodes connected together and then coupled l to bus 570 and thence to bus 450 connected to the positive terminal of battery 20, and (2) to bus 670. The cathode of SCR 650 is connected l by lead 680 to positive bus 130, and (2) through resistor 690 to its gate and through a diode 700, oriented as shown, to the gate of SCR 660. The cathode of SCR 660 has its cathode connected l through resistor 710 to bus 180 (to the cathode of SUS 100) and (2) through resistor 720 to its gate and through resistor 730 to bus 740. Between bus 740 and bus 750 (from bus 670) are connected'a plurality of normally-open panic switches which are distributed throughout the premises.

As noted, the anodes of SCR 650 and SCR 660 are connected together to lead 670 which is connected to one terminal 770 of normally-closed switch 780, the armature 784 of which is connected by lead 783 to the fire alarm portion 790 of System10. The tire alarm portion 790 includes an alarm section 800, a series of sensors 810, and a signal-generating portion 820. The sensors 8l0 are elements, such as thermostats,dispo.sed throughout the premises, and connected between buses 830 and 840 which are terminated by a high resistance potentiometer 850.

The signal-generating portion 820 of the fire alarm portion of the system 10 includes a semiconductor switch, for example, a silicon unilateral switch (SUS) 860 and a silicon controlled rectifier SCR 870. The gate G of SUS 860 is connected 1) through a resistor 880 to bus 783 and (2) to lead 840 to the sensors 810. The anode A of SUS 86.0 is connected through a resistor 890 to bus 783, and the cathode K of SUS 860 is connected by lead 863 l tothe gate of SCR 870 and (2) through a resistor 900 to a junction point 910, to which bus 150 and the cathode of SCR 870 are connected. The junction point 910 is also connected through resistor 920 and a voltmeter 930 to bus 830 to the remote sensors 810.

The alarm portion 800 of the fire alarm system also includes an alarm such as an electromagnetic bell or horn 940, having a different characteristic sound than alarm 30, connected to a filter 950 which is similar in construction to the filter 40 associated with alarm 30 and includes diodes 960 and 970 and coils 980 and 990 interconnected as shown.

Operation of the burlgar alarm portion of the system 10 depends on signal-generating module 90 to sense alarm situations represented by switches S1 and to gen: erate an appropriate signal. With relay 330 set to its normal state, as illustrated in the drawing, positive potential appears on the bus 130 from the battery to lead 460, armature 350, contact 360 and lead 470.

Thus, the signal module 90 is armed and operable. In addition, positive potential runs from lead 470 to lead 328 which is connected to lamps 324 which have their bus 325 connected to negative potential. Thus, lamps 324 light and represent normal status and operability of the signal module 90.

If one of the alarm sensors, represented by switches S1, is triggered, this action being represented by the opening of a switch S1, positive potential is removed from the gate of SUS 100 which thereby conducts and applies a positive pulse to the gate of SCR 280 which then conducts. Conduction of SCR 280 sends a signal to remote circuit 320, and it turns on alarm or horn 30.

Referring to the panic circuit 640, closure of one of the panic switches 760, by an individual on the premises, couples positive potential from battery 20 through leads 570, 670, and 750 and through resistor 730 to the gate of SCR 660. SCR 660 will now conduct and apply a positive pulse through resistor 710 and lead 180 to the cathode of SUS 100 which will conduct and turn on alarm 30, as described above.

If, for some reason, module is disarmed, for example, if there is no positive potential on bus 130, then firing of SCR 660 of the panic module 640 conducts a positive pulse through diode 700 to the gate of SCR 650 which is fired'to apply a positive potential to bus 130. This now permits SUS to tire and operate the alarm 30.

Turning off of the signal module 90 is referred to above and can be accomplished by closing one of the switches 323 associated with the templates 321. When one of these switches is closed, negative potential is coupled from battery 20 over bus 23 and bus 150 to bus 325 to bus 327 to end 343 of winding 340 of relay 330. Current now flows through the winding 340 and causes the arms 350 and 380 thereof to switch so that arm 350 contacts terminal 370 and arm 380 contacts terminal 400. Diode 342 is an inductance suppressor for the winding. With the relay arms thus switched, positive potential, coupled from battery 20, is removed from contact 360 and from bus 470. This removes positive potential from bus and disables the signal module 90. Removing positive potential from bus 470 also turns off lamps 324 of templates 32] throughout the premises. At the same time, positive potential from battery 20 is coupled over switches 51 and bus 430 through arm 380 and contact 400 to bus 326. This causes lamps 322 to light and indicate that alarm module 90 is disabled. However, if a switch S1 is opened, lamps 322 do not light.

Resistor 410 is provided to prevent racing of the relay contacts of relay 330. If arm 380 switches off contact 390 before arm 350 switches to contact 370, a false alarm could occur. Resistor 410 maintains positive potential on bus 420 to prevent this happening.

Reference is now made to exit door 480 and its portion of the system. Before leaving the premises at night and before opening the exit door, switch 510 is closed with a key. This couples negative potential from battery 20 over leads 23, and 630 and closed switch 510 and lead 590 to end 534 of winding 530 of relay 520. Positive potential is applied to the other end of the winding 530 from battery 20 over leads 570 and 563, and the resultant current flow through the winding 530 switches arm 560 from contact 550 to contact 540. This action removes negative potential from bus to SUS 110 of the signal module 90. Now, if the door 480 is opened and door switch 490 is closed, nothing happens in the circuit 90. Switch 510 can be opened by removing the operating key. If now, door 480 is closed, switch 490 opens, and negative potential is removed from winding S30 and arm 560 returns to contact 550 to re-arm SUS 110.

Now, when the premises are opened, for example in the morning, if the premises are a business location, and door 480 is opened to close switch 490, this couples negative potential from battery 20, leads 150 and 630, closed switch 490, bus 640, arm 560 and contact 550 and bus 170 to the gate G of SUS 100. This fires SUS 100 and current flows into the charging circuit associated with UJT 210 and SCR 280. The actual firing of the UJT is delayed by the charging circuit, and this permits an authorized individual time to close switch 510 with his key. This again operates the relay 520 to remove potential from the gate of SUS 100 and to prevent the alarm 30 from being fired. it is noted that lamp 500 turns on when the winding 530 conducts to operate relay 520 to represent disabling of SUS 100.

Referring now to the fire alarm portion 790 of the system, negative potential from battery is coupled thereto over bus 150 and positive potential is coupled from the battery through buses 570 and 670 and closed switch 780 to bus 783. The potentiometer 850 is adjusted to insure that a negative potential is not applied to the gate of SUS 860 which would cause it to turn on, If the potentiometer 850 is adjusted to set meter 930 at center scale, the meter will indicate the condition of battery 20, as well as indicate a complete loop for the fire alarm circuit.

When a fire closes one ofthe thermostats 810, potentiometer 850 is shorted out of the circuit, and this causes a negative potential, or near ground potential, to appear on the gate G of SUS 860. SUS 860 then conducts and applies a positive pulse on bus 863 from the cathode of SUS 860 to the gate of SCR 870 which conducts and causes the fire bell 940 to ring. Opening switch 780 disconnects positive potential from the fire alarm circuit and resets the circuit and the thermostats.

What is claimed is:

l. A burglar-fire alarm system for protecting premises comprising a power supply,

an alarm signal-generating circuit,

a plurality of templates disposed throughout the premises and each including a normal open switch and first and second indicator lamps, said switch and said first and second lamps having a common connection to the negative side of said power sup- P y a double pole relay including a winding, a first pole, and a second pole, said first pole having two contacts and an armature, and said second pole having two contacts and an armature, said first pole being coupled from the positive terminal of said power supply to a portion of said signal-generating circuit which is armed thereby, said second pole being coupled from the positive terminal of said 6 power supply to another portion of said signalgenerating circuit and said first lamp of said templates,

said winding being coupled from said positive terminal of said power supply to said switches of said templates,

a lead from said second lamp of said templates to a portion of said first pole which is connectable to the positive terminal of said power supply,

at least one alarm sensor being connected in circuit with said first pole and said power supply,

a panic circuit including first and second semiconductor switches and at least one panic switch connected across said first semiconductor switch with power connected across it, said first semiconductor switch having a portion coupled to said signalgenerating module for applying power thereto, and said second signal-generating circuit having a portion connected to another portion of said signalgenerating circuit for coupling power thereto,

closure of said panic switch causing said first semiconductor switch to fire and generate a pulse to said second semiconductor switch and to said sig nal-generating circuit, thus causing said semiconductor switch to fire and generate a pulse which is coupled to said signal-generating circuit,

a fire alarm portion coupled through a switch to said panic circuit and to said power supply and including first and second semiconductor switches and thermostatic switches connected to said first semiconductor switch for firing the same, and

an alarm-giving circuit coupled to said semiconductor switches and operated thereby.

2. The system defined in claim 1 and including:

a door-controlled circuit comprising a relay including a winding, an armature, and first and second contacts, said second contact being coupled to said signal-generating circuit, said armature normally being in contact with said second contact and being connected to the fixed contact ofa second switch mounted in a premises door and normally open when said door is closed and closed when said door is open, said switch including an ar mature,

said second contact of said relay being connected to one end of said winding, the other end of which is connected to the positive terminal of said power supply and to the armature of a third switch having a fixed contact connected to both the armature of said second switch and the negative terminal of said power supply,

closure of said third switch by an individual in said premises operating said relay to move said armature to said second contact to disarm said signalgenerating circuit, and opening of said door, closing said second switch.

3. The system defined in claim 1 and including a fire alarm circuit coupled for power to said panic circuit,

said fire alarm circuit including a plurality of fire sensors connected in parallel across a rheostat and across a pulse-generating circuit coupled to a fire alarm-giving circuit, closure of one of said sensors causing said pulse-generating circuit to operate and turn on said fire alarm-giving circuit.

4. The system defined in claim 1 wherein said signalgenerating circuit includes at least one semiconductor device having a plurality of electrodes, said connections from said panic circuit coupling operating potentials to selected ones of said electrodes when said panic circuit operates.

5. The system defined in claim 1 wherein said semi- V conductor switches are silicon-controlled rectifiers having anode, cathode, and gate electrodes, said first and second semiconductor switches having their anodes connected together to positive power supply, said first switch having its cathode connected l to said signal-generating circuit for coupling operating potential thereto and (2) through a diode to the gate of said second switch, the cathode of said second switch being connected to another portion of said signal-generating circuit for coupling operating potential thereto.

6. An alarm system as in claim 1 and including positive and negative buses connected tothe positive and negative terminals, respectively, of said power supply,

a fire alarm-giving means,

a connection from said positive bus through a switch to said fire alarm-giving means,

a plurality of heat-sensing elements connected in parallel with each other and a potentiometer connected in parallel with said heat-sensing elements and adjustable to set the operating level and sensitivity thereof, and

an electrical pulse-generating circuit connected between said heat-sensing elements and said fire alarm-giving .means and operable to operate said alarm when a heat-sensing element is operated by a fire,

said switch being operable to reset said entire system when a fire has operated one of said elements and said alarm-giving means has been operated 7. An alarm system comprising a power supply having positive and negative terminals,

a relay having a first armature and first and second contacts, and a second armature and third and fourth contacts,

an alarm signal-generating circuit having a first bus connected to said negative terminal of said power supply, and a second bus connected to said first contact of said relay,

said first contact also being connected to one terminal of a normal signal light, the second terminal of which is connected to saidnegative terminal of said power supply,

the positioning of said first armature in contact with said first contact representing a normal condition wherein said normal light is ON,

said third contact being connected to a semiconductor switch element in said alarm signal-generating circuit,

said second armature being connected through alarm-sensing elements to said positive terminal of said power supply such that, when said second armature is in contact with said third contact, operation of one of said alarm-sensing elements removes positive'potential from said semiconductor switch element of said alarm signal-generating circuit energizes an alarm, and

a panic circuit including a first semiconductor switch having a first control electrode coupled to a panic switch and to said power supply and having its current flow path connected to said semiconductor switch element and to the gate of a second semiconductor switch having its circuit flow path connected to said second bus of said signal alarmgenerating circuit.

8. The system defined in claim 7 wherein said first and second semiconductor switchs are three-electrode controlled rectifier switches.

9. An alarm system comprising a power supply having positive and negative terminals,

a relay having a winding, a first armature and first and second contacts, and a second armature and third and fourth contacts,

an alarm signal-generating circuit having a plurality of semiconductor switch elements and a first bus connected to said negative terminal of said power supply, and a second bus connected to said first contact of said relay,

a plurality of groups of signal elements dispersed throughout the premises being protected by said alarm system, each group including a normal" light, an alarm light, and a normally open switch,

said first contact of said relay being connected to one terminal of each said normal light, the second terminal'of which is connected to said negative terminal of said power source,

the positioning of said first armature of said relay in contact with said first contact representing 21 normal condition wherein said normal" light is ON,

said third contact of said relay being connected to one semiconductor switch element of said alarm signal-generating circuit,

said second armature of said relay being connected through alarm-sensing elements to said positive terminal of said power supply such that, when said second armature is contact, positive potential is supplied to said alarm signal-generating circuit,

said fourth contact of said relay being connected to one terminal of each second alarm light, the second terminal of which is connected to the negative terminal of said power supply,

said first armature of said relay being normally connected to said second contact of said relay to represent a normal condition, I

operation of one of said alarm-sensing elements serving to remove operating potential from said one semiconductor switch element of said alarm signalgenerating circuit and said circuit energizes an alarm,

closure of one of said normally-open switches causing current flow through said winding and thereby causing movement of both said armatures to said second and fourth contacts, respectively, which thereby removes power from said alarm signalgenerating circuit and disables such alarm signalgenerating circuit, such movement connecting power from said power source to each of said second lights and disconnecting it from each of said first lights, which are thereby turned off, said second lights being turned on to represent disabling of said alarm signal-generating circuit.

10. An alarm system comprising a power supply having positive and negative terminals and positive and negative buses connected thereto,

in contact with said thirda first relay having a winding, a first armature and first and second contacts, and a second armature and third and fourth contacts,

an alarm signal-generating circuit having a plurality of semiconductor elements and a connection to said negative bus and a connection to said relay,

a normally open premises exit switch,

a second relay having a winding, an armature, and

first and second contacts, said winding of said second relay being connected between said positive bus and said first contact of said second relay, said second contact of said second relay being connected to one operating semiconductor element of said alarm signal-generating circuit, said armature of said second relay normally being in contact with said second contact of said second relay and said one semiconductor operating element of said alarm signal-generating circuit,

said normally-open exit switch having first and second contacts, the first contact thereof being connected to said positive bus, said second contact thereof being connected to said first contact of said second relay, and

an exit door having an exit door switch which opens when the door is closed and closes when the door is open, said door switch being connected between said negative bus and said armature of said second relay.

11. An alarm system including a power supply having positive and negative terminals,

a signal-generating circuit,

a premises door,

a first switch mounted in said door and comprising a door switch operated by said door and including a .fixed contact and a movable contact,

a third switch including a fixed contact and a movable contact,

a relay including a relay winding, an armature, and first and second contacts, said second contact being coupled to said signal-generating circuit, said armature normally being in contact with said second contact and being connected to the fixed contact of said door switch, said door switch being normally open when said door is closed and closed when said door is open,

said second contact of said relay being connected to one end of said relay winding, the other end of which is connected to the positive terminal of said power supply and to the movable contact of said third switch, the fixed contact of said third switch being connected to both the movable contact of said second switch and to the negative terminal of said power supply,

closure of said third switch by an individual in said premises operating said relay to move its armature to the first contact of the relay to disarm said signal-generating circuit, and opening of said door causing the closure of said door switch to maintain said signal-generating circuit disarmed while said third switch is opened, whereafter closure of said door and opening of said door switch causing the removal of power from said relay winding and causing said armature to fallback to its second contact to complete a circuit to said signal- I generating circuit for subsequently coupling power thereto when said door is later opened by an occupant of the premises to close said door switch. =1 

1. A burglar-fire alarm system for protecting premises comprising a power supply, an alarm signal-generating circuit, a plurality of templates disposed throughout the premises and each including a normal open switch and first and second indicator lamps, said switch and said first and second lamps having a common connection to the negative side of said power supply, a double pole relay including a winding, a first pole, and a second pole, said first pole having two contacts and an armature, and said second pole having two contacts and an armature, said first pole being coupled from the positive terminal of said power supply to a portion of said signalgenerating circuit which is armed thereby, said second pole being coupled from the positive terminal of said power supply to another portion of said signal-generating circuit and said first lamp of said templates, said winding being coupled from said positive terminal of said power supply to said switches of said templates, a lead from said second lamp of said templates to a portion of said first pole which is connectable to the positive terminal of said power supply, at least one alarm sensor being connected in circuit with said first pole and said power supply, a panic circuit including first and second semiconductor switches and at least one panic switch connected across said first semiconductor switch with power connected across it, said first semiconductor switch having a portion coupled to said signal-generating module for applying power thereto, and said second signal-generating circuit having a portion connected to another portion of said signal-generating circuit for coupling power thereto, closure of said panic switch causing said first semiconductor switch to fire and generate a pulse to said second semiconductor switch and to said signal-generating circuit, thus causing said semiconductor switch to fire and generate a pulse which is coupled to said signal-generating circuit, a fire alarm portion coupled through a switch to said panic circuit and to said power supply and including first and second semiconductor switches and thermostatic switches connected to said first semiconductor switch for firing the same, and an alarm-giving circuit coupled to said semiconductor switches and operated thereby.
 2. The system defined in claim 1 and including: a door-controlled circuit comprising a relay including a winding, an armature, and first and second contacts, said second contact being coupled to said signal-generating circuit, said armature normally being in contact with said second contact and being connected to the fixed contact of a second switch mounted in a premises door and normally open when said door is closed and closed when said door is open, said switch including an armature, said second contact of said relay being connected to one end of said winding, the other end of which is connected to the positive terminal of said power supply and to the armature of a third switch having a fixed contact connected to both the aRmature of said second switch and the negative terminal of said power supply, closure of said third switch by an individual in said premises operating said relay to move said armature to said second contact to disarm said signal-generating circuit, and opening of said door, closing said second switch.
 3. The system defined in claim 1 and including a fire alarm circuit coupled for power to said panic circuit, said fire alarm circuit including a plurality of fire sensors connected in parallel across a rheostat and across a pulse-generating circuit coupled to a fire alarm-giving circuit, closure of one of said sensors causing said pulse-generating circuit to operate and turn on said fire alarm-giving circuit.
 4. The system defined in claim 1 wherein said signal-generating circuit includes at least one semiconductor device having a plurality of electrodes, said connections from said panic circuit coupling operating potentials to selected ones of said electrodes when said panic circuit operates.
 5. The system defined in claim 1 wherein said semiconductor switches are silicon-controlled rectifiers having anode, cathode, and gate electrodes, said first and second semiconductor switches having their anodes connected together to positive power supply, said first switch having its cathode connected (1) to said signal-generating circuit for coupling operating potential thereto and (2) through a diode to the gate of said second switch, the cathode of said second switch being connected to another portion of said signal-generating circuit for coupling operating potential thereto.
 6. An alarm system as in claim 1 and including positive and negative buses connected to the positive and negative terminals, respectively, of said power supply, a fire alarm-giving means, a connection from said positive bus through a switch to said fire alarm-giving means, a plurality of heat-sensing elements connected in parallel with each other and a potentiometer connected in parallel with said heat-sensing elements and adjustable to set the operating level and sensitivity thereof, and an electrical pulse-generating circuit connected between said heat-sensing elements and said fire alarm-giving means and operable to operate said alarm when a heat-sensing element is operated by a fire, said switch being operable to reset said entire system when a fire has operated one of said elements and said alarm-giving means has been operated.
 7. An alarm system comprising a power supply having positive and negative terminals, a relay having a first armature and first and second contacts, and a second armature and third and fourth contacts, an alarm signal-generating circuit having a first bus connected to said negative terminal of said power supply, and a second bus connected to said first contact of said relay, said first contact also being connected to one terminal of a ''''normal'''' signal light, the second terminal of which is connected to said negative terminal of said power supply, the positioning of said first armature in contact with said first contact representing a ''''normal'''' condition wherein said ''''normal'''' light is ON, said third contact being connected to a semiconductor switch element in said alarm signal-generating circuit, said second armature being connected through alarm-sensing elements to said positive terminal of said power supply such that, when said second armature is in contact with said third contact, operation of one of said alarm-sensing elements removes positive potential from said semiconductor switch element of said alarm signal-generating circuit energizes an alarm, and a panic circuit including a first semiconductor switch having a first control electrode coupled to a panic switch and to said power supply and having its current flow path connected to said semiconductor switch element and to the gate of a second semiconductor switch having its circuit flow pAth connected to said second bus of said signal alarm-generating circuit.
 8. The system defined in claim 7 wherein said first and second semiconductor switchs are three-electrode controlled rectifier switches.
 9. An alarm system comprising a power supply having positive and negative terminals, a relay having a winding, a first armature and first and second contacts, and a second armature and third and fourth contacts, an alarm signal-generating circuit having a plurality of semiconductor switch elements and a first bus connected to said negative terminal of said power supply, and a second bus connected to said first contact of said relay, a plurality of groups of signal elements dispersed throughout the premises being protected by said alarm system, each group including a ''''normal'''' light, an ''''alarm'''' light, and a normally open switch, said first contact of said relay being connected to one terminal of each said ''''normal'''' light, the second terminal of which is connected to said negative terminal of said power source, the positioning of said first armature of said relay in contact with said first contact representing a ''''normal'''' condition wherein said ''''normal'''' light is ON, said third contact of said relay being connected to one semiconductor switch element of said alarm signal-generating circuit, said second armature of said relay being connected through alarm-sensing elements to said positive terminal of said power supply such that, when said second armature is in contact with said third contact, positive potential is supplied to said alarm signal-generating circuit, said fourth contact of said relay being connected to one terminal of each second ''''alarm'''' light, the second terminal of which is connected to the negative terminal of said power supply, said first armature of said relay being normally connected to said second contact of said relay to represent a normal condition, operation of one of said alarm-sensing elements serving to remove operating potential from said one semiconductor switch element of said alarm signal-generating circuit and said circuit energizes an alarm, closure of one of said normally-open switches causing current flow through said winding and thereby causing movement of both said armatures to said second and fourth contacts, respectively, which thereby removes power from said alarm signal-generating circuit and disables such alarm signal-generating circuit, such movement connecting power from said power source to each of said second lights and disconnecting it from each of said first lights, which are thereby turned off, said second lights being turned on to represent disabling of said alarm signal-generating circuit.
 10. An alarm system comprising a power supply having positive and negative terminals and positive and negative buses connected thereto, a first relay having a winding, a first armature and first and second contacts, and a second armature and third and fourth contacts, an alarm signal-generating circuit having a plurality of semiconductor elements and a connection to said negative bus and a connection to said relay, a normally open premises exit switch, a second relay having a winding, an armature, and first and second contacts, said winding of said second relay being connected between said positive bus and said first contact of said second relay, said second contact of said second relay being connected to one operating semiconductor element of said alarm signal-generating circuit, said armature of said second relay normally being in contact with said second contact of said second relay and said one semiconductor operating element of said alarm signal-generating circuit, said normally-open exit switch having first and second contacts, the first contact thereof being connected to said positive bus, said second contact thereof being connected to said first contact of said second relay, and an exit door having an exit door switch which opens when the door is closed and closes when the door is open, said door switch being connected between said negative bus and said armature of said second relay.
 11. An alarm system including a power supply having positive and negative terminals, a signal-generating circuit, a premises door, a first switch mounted in said door and comprising a door switch operated by said door and including a fixed contact and a movable contact, a third switch including a fixed contact and a movable contact, a relay including a relay winding, an armature, and first and second contacts, said second contact being coupled to said signal-generating circuit, said armature normally being in contact with said second contact and being connected to the fixed contact of said door switch, said door switch being normally open when said door is closed and closed when said door is open, said second contact of said relay being connected to one end of said relay winding, the other end of which is connected to the positive terminal of said power supply and to the movable contact of said third switch, the fixed contact of said third switch being connected to both the movable contact of said second switch and to the negative terminal of said power supply, closure of said third switch by an individual in said premises operating said relay to move its armature to the first contact of the relay to disarm said signal-generating circuit, and opening of said door causing the closure of said door switch to maintain said signal-generating circuit disarmed while said third switch is opened, whereafter closure of said door and opening of said door switch causing the removal of power from said relay winding and causing said armature to fall back to its second contact to complete a circuit to said signal-generating circuit for subsequently coupling power thereto when said door is later opened by an occupant of the premises to close said door switch. 